Concomitant Filled Prescriptions of Oxymorphone or Oxycodone with CYP3A Inhibitors and Inducers.

BACKGROUND: Oxymorphone's metabolism does not involve the hepatic cytochrome P450 (CYP) system. The effect of this pharmacokinetic feature of oxymorphone on opioid prescribing is unknown. OBJECTIVE: To assess the relative frequency with which oxymorphone and oxycodone (a CYP3A-metabolized opioid analgesic) were each prescribed to patients concomitantly receiving CYP3A-modifying drugs (i.e., inducers and inhibitors) to characterize opioid-prescribing patterns in patients at risk for CYP3A-related drug interactions. METHODS: We analyzed the Sentinel Distributed Database from January 1, 2013, to December 31, 2016, to identify the proportion of patients with concomitant dispensing of selected CYP3A modifiers among initiators of oxymorphone. We then repeated the analysis using oxycodone instead of oxymorphone. We conducted sensitivity analyses that varied the washout periods for each opioid to account for potential opioid switching. RESULTS: In the primary analysis, the proportion of patients with concomitant incident dispensings of oxymorphone and selected CYP3A modifiers was 3.26% (95% CI = 3.09%-3.43%), and the proportion of patients with incident dispensings of oxycodone and selected CYP3A modifiers was 2.82% (95% CI = 2.79%-2.85%). The difference between proportions was 0.43% (95% CI = 0.26%-0.60%). Sensitivity analyses that varied the washout periods for each opioid with respect to the other opioid to account for switching yielded similar results. CONCLUSIONS: We observed similar proportions of patients using selected CYP3A modifiers concomitantly with both oxymorphone and oxycodone. While the CIs of the point estimates did not overlap, the absolute differences between the proportions were small. DISCLOSURES: This project was supported by Task Order HHSF22301001T under Master Agreement HHSF223201400030I from the U.S. Food and Drug Administration (FDA). The FDA approved the study protocol, including the statistical analysis plan, and reviewed and approved the manuscript. Coauthors from the FDA participated in the results interpretation and in the preparation and decision to submit the manuscript for publication. Coyle, Money, Staffa, Meyer, and Woods are employed by the FDA. The other authors have no financial conflicts of interest to report. The views expressed are those of the authors and not necessarily those of the U.S. Department of Health and Human Services, U.S. Food and Drug Administration.

Pediatric Drug Labeling and Imperfect Information.

I first became aware of bioethics in the spring of 1980. I had spent a thirty-six-hour shift shadowing a medical resident, and I was struck that many of the resident's decisions had ethical dimensions. The next day, I came across the Hastings Center Report, and I realized I wanted to explore ethical issues I found implicit in clinical care, even though I still wanted to become a pediatrician. In September 2019, when I attended my first meeting of the U.S. Food and Drug Administration's Pediatric Advisory Committee, as a pediatric pulmonologist, I had the same sense of awe and curiosity that I had forty years ago. What had appeared initially as somewhat technical decisions about the regulation of drug labeling was suffused with ethical questions. The committee was asked to discuss possible changes to the labeling of two previously approved drugs.

Pharmacokinetics of oxycodone/naloxone and its metabolites in patients with end-stage renal disease during and between haemodialysis sessions.

BACKGROUND: The pharmacokinetics of oxycodone in patients with end-stage renal disease (ESRD) requiring haemodialysis are largely unknown. Therefore, we investigated the pharmacokinetics of oxycodone/naloxone prolonged release and their metabolites in patients with ESRD during and between haemodialysis sessions. METHODS: Single doses of oxycodone/naloxone (5/2.5 or 10/5 mg) were administered in nine patients with ESRD using a cross-over design on the day of dialysis and on a day between dialysis sessions. Plasma, dialysate and urine concentrations of oxycodone, naloxone and their metabolites were determined up to 48 h post-dosing using a liquid chromatography-tandem mass spectrometry system. RESULTS: Haemodialysis performed 6-10 h after dosing removed ∼10% of the administered dose of oxycodone predominantly as unconjugated oxycodone and noroxycodone or conjugated oxymorphone and noroxymorphone. The haemodialysis clearance of oxycodone based on its recovery in dialysate was (mean ± SD) 8.4 ± 2.1 L/h. The geometric mean (coefficient of variation) plasma elimination half-life of oxycodone during the 4-h haemodialysis period was 3.9 h (39%) which was significantly shorter than the 5.7 h (22%) without haemodialysis. Plasma levels of the active metabolite oxymorphone in its unconjugated form were very low. CONCLUSIONS: Oxycodone is removed during haemodialysis. The pharmacokinetics including the relatively short half-life of oxycodone in patients with ESRD with or without haemodialysis and the absence of unconjugated active metabolites indicate that oxycodone can be used at usual doses in patients requiring dialysis.

Acute kidney injury is common with intravenous abuse of extended-release oral oxymorphone and delayed renal recovery rates are associated with increased KDIGO staging.

AIM: Prescription opioid abuse poses a serious problem in the United States, representing 615 per 100 000 deaths annually. Extended-release oxymorphone (Opana-ER) is an oral opioid pain medication that has recently been found to cause thrombotic microangiopathy when intravenously abused. In this retrospective study, we attempted to determine the prevalence and outcomes of acute kidney injury (AKI) among patients intravenously abusing extended-release oral oxymorphone. METHODS: A query of electronic medical records for 'drug abuse' at an academic medical centre during January 2012 to December 2015 was performed and yielded 2350 patients. Patients were further identified by documented intravenous abuse of extended-release oxymorphone. Patients were stratified based on multiple renal indices and outcomes. Potential confounders were also identified. RESULTS: One hundred and sixty-five patients were found to have a documented history of intravenous abuse of extended-release oral oxymorphone. Prevalence of AKI in this population was a 47.8%. KDIGO stage-I patients consisted of 17.8% of patients with AKI, 40.5% were classified as KDIGO stage-II AKI, and 41.8% were classified as KDIGO stage-III AKI. Among patients with AKI, average age was found to be 37.5 years, 59.4% experienced renal recovery, 56.9% required intensive care unit admission, 13.9% progressed to end-stage renal disease (ESRD), and 7.6% expired during admission. CONCLUSION: Clinicians should be educated to help recognize intravenous abuse of extended-release oral oxymorphone and its associated effects. Our data suggests AKI is common in these patients; higher KDIGO staging appears to be associated with slower rates of renal recovery, increased comorbidities and progression to both CKD and ESRD.

Multiple injections per injection episode: High-risk injection practice among people who injected pills during the 2015 HIV outbreak in Indiana.

BACKGROUND: Misuse of prescription opioid analgesics (POA) has increased dramatically in the US, particularly in non-urban areas. We examined injection practices among persons who inject POA in a rural area that experienced a large HIV outbreak in 2015. METHODS: Between August-September 2015, 25 persons who injected drugs within the past 12 months were recruited in Scott County, Indiana for a qualitative study. Data from in-depth, semi-structured interviews were analyzed. RESULTS: All 25 participants were non-Hispanic white and the median age was 33 years (range: 19-57). All had ever injected extended-release oxymorphone (Opana® ER) and most (n=20) described preparing Opana® ER for multiple injections per injection episode (MIPIE). MIPIE comprised 2-4 injections during an injection episode resulting from needing >1mL water to prepare Opana® ER solution using 1mL syringes and the frequent use of "rinse shots." MIPIE occurred up to 10 times/day (totaling 35 injections/day), often in the context of sharing drug and injection equipment. CONCLUSIONS: We describe a high-risk injection practice that may have contributed to the rapid spread of HIV in this community. Efforts to prevent bloodborne infections among people who inject POA need to assess for MIPIE so that provision of sterile injection equipment and safer injection education addresses the MIPIE risk environment.

Oxymorphone Hydrochloride Extended-Release (OPANA®) Associated With Acute Kidney Injury in a Chronic Pain Patient: A Case Report.

Oxymorphone hydrochloride extended-release (OPANA®) is an opioid prescribed for the treatment of moderate-to-severe chronic pain. Kidney injury related to its use has not previously been reported. We present a case of a chronic pain patient with underlying chronic renal insufficiency who developed superimposed acute kidney injury when his opioid analgesic was changed from morphine sulfate extended-release to OPANA. Electron microscopy of his renal tissue revealed lamellated podocytes typically seen with drug-induced phospholipidosis.

A mechanistic investigation of thrombotic microangiopathy associated with IV abuse of Opana ER.

Since 2012, a number of case reports have described the occurrence of thrombotic microangiopathy (TMA) following IV abuse of extended-release oxymorphone hydrochloride (Opana ER), an oral opioid for long-term treatment of chronic pain. Here, we present unique clinical features of 3 patients and investigate IV exposure to the tablet's inert ingredients as a possible causal mechanism. Guinea pigs were used as an animal model to understand the hematopathologic and nephrotoxic potential of the inert ingredient mixture (termed here as PEO+) which primarily contains high-molecular-weight polyethylene oxide (HMW PEO). Microangiopathic hemolytic anemia, thrombocytopenia, and acute kidney injury were found in a group of 3 patients following recent injection of adulterated extended-release oxymorphone tablets. Varying degrees of cardiac involvement and retinal ischemia occurred, with TMA evident on kidney biopsy. A TMA-like state also developed in guinea pigs IV administered PEO+. Acute tubular and glomerular renal injury was accompanied by nonheme iron deposition and hypoxia-inducible factor-1α upregulation in the renal cortex. Similar outcomes were observed following dosing with HMW PEO alone. IV exposure to the inert ingredients in reformulated extended-release oxymorphone can elicit TMA. Although prescription opioid abuse shows geographic variation, all physicians should be highly inquisitive of IV drug abuse when presented with cases of TMA.

Effect of morphine, methadone, hydromorphone or oxymorphone on the thermal threshold, following intravenous or buccal administration to cats.

OBJECTIVE: To determine the effects of morphine, methadone, hydromorphone or oxymorphone on the thermal threshold in cats, following buccal and intravenous (IV) administration. STUDY DESIGN: Randomized crossover study. ANIMALS: Six healthy adult female ovariohysterectomized cats weighing 4.5 ± 0.4 kg. METHODS: Morphine sulfate (0.2 mg kg-1 IV or 0.5 mg kg-1 buccal), methadone hydrochloride (0.3 mg kg-1 IV or 0.75 mg kg-1 buccal), hydromorphone hydrochloride (0.1 mg kg-1 IV or 0.25 mg kg-1 buccal) or oxymorphone hydrochloride (0.1 mg kg-1 IV or 0.25 mg kg-1 buccal) were administered. All cats were administered all treatments. Skin temperature and thermal threshold were measured in duplicate prior to drug administration, and at various times up to 8 hours after drug administration. The difference between thermal threshold and skin temperature (ΔT) was analyzed. RESULTS: Administration of methadone and hydromorphone IV resulted in significant increases in ΔT at 40 minutes after drug administration. Buccal administration of methadone resulted in significant increases in thermal threshold, although no significant difference from baseline measurement was detected at any time point. IV administration of morphine and oxymorphone, and buccal administration of morphine, hydromorphone and oxymorphone did not cause significant thermal antinociception. CONCLUSION AND CLINICAL RELEVANCE: At the doses used in this study, IV administration of methadone and hydromorphone, and buccal administration of methadone resulted in transient thermal antinociception. The results of this study do not allow us to predict the usefulness of these drugs for providing analgesia in clinical patients.

New Initiation of Long-Acting Opioids in Long-Stay Nursing Home Residents.

OBJECTIVES: To estimate the prevalence of new initiation of long-acting opioids since introduction of national efforts to increase prescriber and public awareness on safe use of transdermal fentanyl patches. DESIGN: Cross-sectional. SETTING: U.S. nursing homes (NHs). PARTICIPANTS: Medicare-enrolled long-stay NH residents (N = 22,253). MEASUREMENTS: Minimum Data Set 3.0 was linked with Medicare enrollment, hospital claims, and prescription drug transaction data (January-December 2011) and used to determine the prevalence of new initiation of a long-acting opioid prescribed to residents in NHs. RESULTS: Of NH residents prescribed a long-acting opioid within 30 days of NH admission (n = 12,278), 9.4% (95% confidence interval = 8.9-9.9%) lacked a prescription drug claim for a short-acting opioid in the previous 60 days. The most common initial prescriptions of long-acting opioids were fentanyl patch (51.9% of opioid-naïve NH residents), morphine sulfate (28.1%), and oxycodone (17.2%). CONCLUSION: New initiation of long-acting opioids-especially fentanyl patches, which have been the subject of safety communications-persists in NHs.

HIV Infection Linked to Injection Use of Oxymorphone in Indiana, 2014-2015.

BACKGROUND: In January 2015, a total of 11 new diagnoses of human immunodeficiency virus (HIV) infection were reported in a small community in Indiana. We investigated the extent and cause of the outbreak and implemented control measures. METHODS: We identified an outbreak-related case as laboratory-confirmed HIV infection newly diagnosed after October 1, 2014, in a person who either resided in Scott County, Indiana, or was named by another case patient as a syringe-sharing or sexual partner. HIV polymerase (pol) sequences from case patients were phylogenetically analyzed, and potential risk factors associated with HIV infection were ascertained. RESULTS: From November 18, 2014, to November 1, 2015, HIV infection was diagnosed in 181 case patients. Most of these patients (87.8%) reported having injected the extended-release formulation of the prescription opioid oxymorphone, and 92.3% were coinfected with hepatitis C virus. Among 159 case patients who had an HIV type 1 pol gene sequence, 157 (98.7%) had sequences that were highly related, as determined by phylogenetic analyses. Contact tracing investigations led to the identification of 536 persons who were named as contacts of case patients; 468 of these contacts (87.3%) were located, assessed for risk, tested for HIV, and, if infected, linked to care. The number of times a contact was named as a syringe-sharing partner by a case patient was significantly associated with the risk of HIV infection (adjusted risk ratio for each time named, 1.9; P<0.001). In response to this outbreak, a public health emergency was declared on March 26, 2015, and a syringe-service program in Indiana was established for the first time. CONCLUSIONS: Injection-drug use of extended-release oxymorphone within a network of persons who inject drugs in Indiana led to the introduction and rapid transmission of HIV. (Funded by the state government of Indiana and others.).

Prescription Opioids. V. Metabolism and Excretion of Oxymorphone in Urine Following Controlled Single Dose Administration.

Oxymorphone (OM), a prescription opioid and metabolite of oxycodone, was included in the recently published proposed revisions to the Mandatory Guidelines for Federal Workplace Drug Testing Programs. To facilitate toxicological interpretation, this study characterized the time course of OM and its metabolite, noroxymorphone (NOM), in hydrolyzed and non-hydrolyzed urine specimens. Twelve healthy subjects were administered a single 10 mg controlled-release OM dose, followed by a periodic collection of pooled urine specimens for 54 h following administration. Analysis for free and total OM and NOM was conducted by liquid chromatography tandem mass spectrometry (LC-MS-MS), at a 50 ng/mL limit of quantitation (LOQ). Following enzymatic hydrolysis, OM and NOM were detected in 89.9% and 13.5% specimens, respectively. Without hydrolysis, OM was detected in 8.1% specimens, and NOM was not detected. The mean ratio of hydrolyzed OM to NOM was 41.6. OM was frequently detected in the first pooled collection 0-2 h post-dose, appearing at a mean of 2.4 h. NOM appeared at a mean of 8.3 h. The period of detection at the 50 ng/mL threshold averaged 50.7 h for OM and 11.0 h for NOM. These data support that OM analysis conducted using a 50 ng/mL threshold should include hydrolysis or optimize sensitivity for conjugated OM.

THROMBOTIC MICROANGIOPATHY ASSOCIATED WITH OPANA ER INTRAVENOUS ABUSE A Case Report.

Thrombotic microangiopathy is characterized by endothelial changes and microvascular stenosis. Several entities such as pregnancy, infection, connective tissue diseases, and drugs are associated with secondary thrombotic microangiopathy. Recently, new reformulation of Opana ER had been associated with thrombotic microangiopathy when injected intravenously. Here, we report the case of a 37-year-old man who developed renal failure and hemolytic anemia secondary to Opana ER intravenous abuse. Renal biopsy pathology was consistent with thrombotic microangiopathy likely caused by Opana ER intravenous abuse.

A tale of 2 ADFs: differences in the effectiveness of abuse-deterrent formulations of oxymorphone and oxycodone extended-release drugs.

The introduction of extended-release opioid analgesics helped initiate an epidemic of prescription opioid abuse in the United States. To make access to the drug by crushing or dissolution more difficult, abuse-deterrent formulations (ADFs) of OxyContin (Purdue Pharma, Stamford, CT) and Opana ER (Endo Pharmaceuticals Inc., Malvern, PA), which use the same foundation technology (Intac, Grunenthal, Aachen, Germany), were introduced in 2010 and 2012, respectively. To examine their relative effectiveness, we used a structured survey of 12,124 individuals entering treatment for opioid use disorder followed by a more focused online survey with a subset of these patients (N = 129) using both structured and open-ended questions. Data showed that the OxyContin ADF was highly effective in reducing nonoral abuse (91.4% before the ADF, 47.9% afterwards), particularly with insufflation (78%-28.8%) and intravenous injection of the active drug (42.7%-21.4%). However, although the Opana ER ADF was effective in reducing insufflation (80%-37.1%), injection (60.0%-51.4%), and overall nonoral abuse (94.3%-77.1%), it showed no significant decrease over time. Bearing in mind that the Opana ER sample was smaller in size than that for OxyContin, our results nonetheless suggest disparate outcomes resulting from the introduction of the ADFs, which could indicate that an ADF's effectiveness may be drug-specific. Given the public health impact of prescription opioids and the considerable effort being expended to develop ADFs as a partial solution to the problem, our preliminary studies suggest that each ADF must be evaluated on its own merits even if the same proprietary technology is used.

Pharmacodynamic effects of oral oxymorphone: abuse liability, analgesic profile and direct physiologic effects in humans.

Oxymorphone is a semisynthetic µ-opioid agonist, marketed as a prescription analgesic purported to be twice as potent as oxycodone for pain relief. Oral formulations of oxymorphone were reintroduced in the United States in 2006 and reports of abuse ensued; however, there are limited data available on its pharmacodynamic effects. The current study aimed to examine the direct physiologic effects, relative abuse liability, analgesic profile and overall pharmacodynamic potency of oxymorphone in comparison with identical doses of oxycodone. Healthy, non-dependent opioid abusers (n = 9) were enrolled in this within-subject, double-blind, placebo-controlled, 3-week inpatient study. Seven experimental sessions (6.5 hours) were conducted, during which an oral dose of immediate-release formulations of oxymorphone (10, 20 and 40 mg), oxycodone (10, 20 and 40 mg) or placebo was administered. An array of physiologic, abuse liability and experimental pain measures was collected. At identical doses, oxymorphone produced approximately twofold less potent effects on miosis, compared with oxycodone. Oxymorphone also produced lesser magnitude effects on measures of respiratory depression, two experimental pain models and observer-rated agonist effects. However, 40 mg of oxymorphone was similar to 40 mg of oxycodone on several abuse-related subjective ratings. Formal relative potency analyses were largely invalid because of the substantially greater effects of oxycodone. Overall, oxymorphone is less potent on most pharmacodynamic measures, although at higher doses, its abuse liability is similar to oxycodone. These data suggest that the published clinical equianalgesic estimates may not be consistent with the observed direct physiologic effects of opioids, results of experimental pain models or abuse liability measures, as assessed in the human laboratory.

Effects of oxymorphone hydrochloride or hydromorphone hydrochloride on minimal alveolar concentration of desflurane in sheep.

OBJECTIVE: To establish the minimum alveolar concentration (MAC) of desflurane and evaluate the effects of 2 opioids on MAC in sheep. ANIMALS: 8 adult nulliparous mixed-breed sheep. PROCEDURES: A randomized crossover design was used. Each sheep was evaluated individually on 2 occasions (to allow assessment of the effects of each of 2 opioids), separated by a minimum of 10 days. On each occasion, sheep were anesthetized with desflurane in 100% oxygen, MAC of desflurane was determined, oxymorphone (0.05 mg/kg) or hydromorphone (0.10 mg/kg) was administered IV, and MAC was redetermined. Physiologic variables and arterial blood gas and electrolyte concentrations were measured at baseline (before MAC determination, with end-tidal desflurane concentration maintained at 10%) and each time MAC was determined. Timing of various stages of anesthesia was recorded for both occasions. RESULTS: Mean ± SEM MAC of desflurane was 8.6 ± 0.2%. Oxymorphone or hydromorphone administration resulted in significantly lower MAC (7.6 ± 0.4% and 7.9 ± 0.2%, respectively). Cardiac output at MAC determination for desflurane alone and for desflurane with opioid administration was higher than that at baseline. No difference was identified among hematologic values at any point. Effects of oxymorphone and hydromorphone on durations of various stages of anesthesia did not differ significantly. CONCLUSIONS AND CLINICAL RELEVANCE: MAC of desflurane in nulliparous adult sheep was established. Intravenous administration of oxymorphone or hydromorphone led to a decrease in MAC; however, the clinical importance of that decrease was minor relative to the effect in other species.

Acute Sensorineural Hearing Loss After Abuse of an Inhaled, Crushed Oxymorphone Extended-Release Tablet.

Oxymorphone, a semisynthetic µ-opioid receptor agonist, is the major active metabolite of oxycodone. It is a highly potent narcotic analgesic due to its high lipid solubility, which allows it to readily cross the blood-brain barrier and enter the central nervous system. It is available as both an immediate-release and extended-release (ER) formulation. Oxymorphone can be abused by injection or inhalation of crushed tablets; thus, in 2011, the manufacturer of ER oxymorphone reformulated the drug with crush-resistant technology to deter its misuse and abuse. We describe the case of a previously healthy, 24-year-old male who experienced reproducible acute subjective bilateral temporary hearing loss that occurred after inhalation of oxymorphone. He presented to the emergency department complaining of acute bilateral hearing loss after he reported snorting a crushed oxymorphone ER 30-mg tablet. Emergency department evaluation revealed obvious bilateral hearing loss as well as coincidental aspiration pneumonia. The patient's medical history revealed that he had experienced a similar episode of hearing loss after a previous episode of oxymorphone inhalation. His hearing loss began to improve 3 hours after presentation to the emergency department and was completely resolved by the following day. Use of the Naranjo adverse drug reaction probability scale revealed oxymorphone to be a probable cause of this patient's acute hearing loss (score of 6). The mechanism of action of opioid-associated hearing loss (OAHL) is not completely understood, but it is thought to be due to disturbances within the cochlea, such as cochlear ischemia. To our knowledge, this is only the second published case report of acute reversible hearing loss following oxymorphone inhalation and the first published case report of reproducible OAHL. Since opioid misuse continues to be prevalent despite attempts at reformulations to make the drugs crush resistant, a high degree of clinical suspicion is needed to evaluate and treat patients who present with unique findings after episodes of substance abuse, especially those related to tamper-resistant formulations.

Community Outbreak of HIV Infection Linked to Injection Drug Use of Oxymorphone--Indiana, 2015.

On January 23, 2015, the Indiana State Department of Health (ISDH) began an ongoing investigation of an outbreak of human immunodeficiency virus (HIV) infection, after Indiana disease intervention specialists reported 11 confirmed HIV cases traced to a rural county in southeastern Indiana. Historically, fewer than five cases of HIV infection have been reported annually in this county. The majority of cases were in residents of the same community and were linked to syringe-sharing partners injecting the prescription opioid oxymorphone (a powerful oral semi-synthetic opioid analgesic). As of April 21, ISDH had diagnosed HIV infection in 135 persons (129 with confirmed HIV infection and six with preliminarily positive results from rapid HIV testing that were pending confirmatory testing) in a community of 4,200 persons.

Use of prescription opioids with abuse-deterrent technology to address opioid abuse.

OBJECTIVE: The development of new formulations of extended-release (ER) opioids with abuse-deterrent technology attempts to deter prescription opioid abuse while maintaining appropriate access to care for pain patients. This study examined the degree to which some patients may avoid switching to reformulated ER opioids with abuse-deterrent technology and the extent to which those patients are more likely to be abusers. RESEARCH DESIGN AND METHODS: We analyzed Truven MarketScan pharmacy and medical claims data following the introduction of two reformulated ER opioids with abuse-deterrent technology. Adults aged 18-64 who were continuous users of extended-release oxycodone HCl (ER oxycodone) or extended-release oxymorphone HCl (ER oxymorphone) in a 6 month period prior to the introduction of the respective reformulations of those products were identified and categorized based on whether they switched to the reformulation, switched to other ER/long-acting (LA) opioids (without abuse-deterrent technology), or discontinued ER/LA opioid treatment in a 6 month post-reformulation period. Abusers were identified using ICD-9-CM diagnosis codes for opioid abuse/dependence. Pearson's chi-squared tests and Fisher's exact tests were then used to compare rates of abuse between patients who avoided switching to a reformulated ER opioid. Sensitivity analyses examined several definitions used in this analysis. MAIN OUTCOME MEASURES: ER/LA opioid utilization; rates of diagnosed opioid abuse. RESULTS: A total of 31%-50% of patients avoided switching to reformulated ER opioids. Rates of diagnosed opioid abuse were higher among these patients compared to patients who transitioned to the reformulated ER opioids. LIMITATIONS: Due to the observational research design, caution is warranted in causal interpretation of the findings. The study was conducted among commercially insured continuous ER oxycodone or ER oxymorphone users; future research should consider additional patient populations, such as non-continuous users and those without commercial insurance (i.e., Medicare, Medicaid, uninsured). CONCLUSIONS: Some patients switched to other ER/LA opioids without abuse-deterrent technology or discontinued ER/LA opioid treatment when their existing ER treatment was reformulated. Rates of opioid abuse were higher among patients who switched to other ER/LA opioids or discontinued ER/LA opioid treatment, suggesting that abusers may seek more easily abuseable alternatives such as prescription opioids without abuse-deterrent technology.